Network chip and network transmission/reception device

Abstract

Provided is a network chip that controls issuance of interrupts based on the contents of the received packets. The network chip receives a data packet containing a type that indicates a realtime packet or a not-realtime packet, where the realtime packet needs consideration of delay time, and the not-realtime packet does not need consideration of delay time. The network chip obtains a type by analyzing the received packet. When the obtained type indicates a realtime packet, the network chip stores the received packet into a realtime reception packet buffer, and issues an interrupt to the CPU immediately; and when the obtained type indicates a not-realtime packet, it stores the received packet into a not-realtime reception packet buffer, and issues an interrupt to the CPU after a predetermined time period passes, or after the number of packets stored in the not-realtime reception packet buffer reaches a predetermined number.

1 . A network chip that is provided together with a central processing unit in a device and transmits and receives data packets to/from an external device that is connected thereto by a network, the network chip comprising:
 an analyzing unit operable to analyze a data packet received from the external device;   a judging unit operable to judge, in accordance with a result of the analysis of the received data packet, whether or not an interrupt should be immediately issued to the central processing unit to request processing of the received data packet;   a timer unit operable to, when the judging unit judges that the interrupt should not be immediately issued, start measuring a time, and after a predetermined time period passes thereafter, make a notification that the interrupt should be issued; and   a control unit operable to issue the interrupt to the central processing unit, in accordance with either the analysis result or the notification made by the timer unit.   
     
     
         2 . The network chip of  claim 1 , wherein
 the data packet includes an attribute that indicates a level of importance of the data packet,   the analyzing unit analyzes the attribute of the data packet received from the external device,   the judging unit judges, in accordance with a result of the analysis of the attribute, whether or not the received data packet is important, and   the control unit issues the interrupt immediately to the central processing unit when the judging unit judges that the received data packet is important.   
     
     
         3 . The network chip of  claim 2 , wherein
 the attribute is type information that indicates a type of the data packet that is either a realtime packet or a not-realtime packet, where the realtime packet needs consideration of delay time, and the not-realtime packet does not need consideration of delay time,   the analyzing unit obtains a type from the received data packet by analyzing the received data packet, and   the judging unit judges that the received data packet is important when the type obtained by the analyzing unit indicates the realtime packet.   
     
     
         4 . The network chip of  claim 2 , wherein
 the attribute is application information that indicates an application by which the data packet should be processed,   the network chip is, connected to the network but is not connected in an application level, and preliminarily stores specification information that indicates an application specified by the central processing unit,   the analyzing unit analyzes whether or not the received data packet is a data packet of an application, and   when the analyzing unit analyzes that the received data packet is a data packet of an application, the judging unit judges, in accordance with the application information included in the received data packet, whether or not the received data packet is a data packet of the application indicated by the specification information, and judges that the received data packet is important when the judging unit judges that the received data packet is a data packet of the application indicated by the specification information.   
     
     
         5 . The network chip of  claim 4 , wherein
 the application information is a first port number for identifying an application by which the data packet should be processed,   the specification information is a second port number for identifying the application specified by the central processing unit, and   the judging unit judges that the received data packet is a data packet of the application indicated by the specification information when the first port number matches the second port number.   
     
     
         6 . The network chip of  claim 2 , wherein
 the attribute is a network identifier for identifying the network,   the network chip is not connected to the network and preliminarily stores a specification identifier for identifying a network specified by the central processing unit,   the analyzing unit obtains the network identifier from the received data packet by analyzing the received data packet, and   the judging unit judges whether or not the network identifier obtained from the received data packet matches the preliminarily stored specification identifier, and judges that the received data packet is important when the judging unit judges that the network identifier matches the specification identifier.   
     
     
         7 . The network chip of  claim 6 , wherein
 the data packet including the network identifier is a beacon packet,   the analyzing unit obtains the network identifier from the received beacon packet by analyzing the received beacon packet, and   the judging unit judges whether or not the network identifier obtained from the received beacon packet matches the specification identifier.   
     
     
         8 . The network chip of  claim 2 , wherein
 the attribute is destination information that indicates a transmission destination of the data packet,   the analyzing unit obtains the destination information by analyzing the received data packet, and   the judging unit judges whether or not the transmission destination indicated by the destination information is the device that includes the network chip, and judges that the received data packet is important when the judging unit judges that the transmission destination indicated by the destination information is the device that includes the network chip.   
     
     
         9 . The network chip of  claim 8 , wherein
 the destination information is a destination IP address for identifying a transmission destination device,   the network chip preliminarily stores a device IP address that is assigned to the device that includes the network chip, and   the judging unit judges that the data packet is destined for the device that includes the network chip when the device IP address matches the destination IP address.   
     
     
         10 . The network chip of  claim 1 , wherein
 the received data packet includes type information that indicates a type of the data packet that is either a realtime packet or a not-realtime packet, where the realtime packet needs consideration of delay time, and the not-realtime packet does not need consideration of delay time,   the central processing unit processes one or more realtime packets stored in a predetermined storage area in a transmission process in which one or more data packets are transmitted to the external device,   the network chip manages times at which the one or more data packets are transmitted in the transmission process,   the analyzing unit obtains the type information from the received data packet, and stores the received data packet into the predetermined storage area when the type information indicates the realtime packet,   when the type information indicates the realtime packet, the judging unit judges whether or not a time period until a next data packet transmission is equal to or larger than a predetermined time period that is allowed for as a delay time, and   the control unit issues the interrupt immediately to the central processing unit when the judging unit judges that the time period until the next data packet transmission is equal to or larger than the predetermined time period.   
     
     
         11 . The network chip of  claim 10 , wherein
 the network chip includes a time storage are a preliminarily storing a transmission time interval at which data packets are transmitted, and manages the times at which the one or more data packets are transmitted, in accordance with the transmission time interval.   
     
     
         12 . The network chip of  claim 10 , wherein
 the network chip preliminarily stores history information that indicates transmission times at which a plurality of data packets were transmitted respectively in past, and   the judging unit detects a transmission time at which a next data packet is to be transmitted, in accordance with the history information, and judges whether the detected transmission time is within a predetermined time range.   
     
     
         13 . The network chip of  claim 1 , wherein
 data packets transmitted from the external device are classified into a plurality of types,   the external device transmits data packets of a same type to the network chip in one burst transfer period, where a plurality of burst transfer periods are provided respectively in correspondence with the plurality of types of data packets,   the network chip preliminarily stores time periods of the plurality of burst transfer periods that correspond to the plurality of types of data packets, and receives data packets of a same type in one burst transfer period,   the analyzing unit analyzes a data packet that is received first in a burst transfer period and obtains a time period of the burst transfer period corresponding to a type of the received data packet,   the judging unit judges whether or not a current time is within the burst transfer period based on the obtained time period of the burst transfer period, and   the control unit does not issue the interrupt immediately to the central processing unit when the judging unit judges that the current time is within the burst transfer period.   
     
     
         14 . The network chip of  claim 13 , wherein
 the network chip stores one or more data packets, which were received during an interrupt process, into a predetermined packet storage area,   after a burst transfer is completed, the judging unit judges whether a predetermined time period has passed since a receipt of a start data packet that is stored first in the predetermined packet storage area, and whether number of data packets stored in the predetermined packet storage area is equal to or larger than a predetermined number, and   the control unit issues the interrupt immediately to the central processing unit when the judging unit judges either that the predetermined time period has passed since the receipt of the start data packet or that the number of data packets stored in the predetermined packet storage area is equal to or larger than the predetermined number.   
     
     
         15 . The network chip of  claim 13 , wherein
 after a burst transfer is completed, the judging unit judges that the interrupt should be immediately issued, and the control unit issues the interrupt immediately to the central processing unit when the judging unit judges that the interrupt should be immediately issued.   
     
     
         16 . A network transmission/reception device comprising a central processing unit and a network chip that transmits and receives data packets to/from an external device that is connected thereto by a network, wherein
 the network chip includes:   an analyzing unit operable to analyze a data packet received from the external device;   a judging unit operable to judge, in accordance with a result of the analysis of the received data packet, whether or not an interrupt should be immediately issued to the central processing unit to request processing of the received data packet;   a timer unit operable to, when the judging unit judges that the interrupt should not be immediately issued, start measuring a time, and after a predetermined time period passes thereafter, make a notification that the interrupt should be issued; and   a control unit operable to issue the interrupt to the central processing unit, in accordance with either the analysis result or the notification made by the timer unit, wherein   the central processing unit processes the received data packet when the central processing unit receives the interrupt issued from the network chip.   
     
     
         17 . The network transmission/reception device of  claim 16 , wherein
 the data packet includes an attribute that indicates a level of importance of the data packet,   the analyzing unit analyzes the attribute of the data packet received from the external device,   the judging unit judges, in accordance with a result of the analysis of the attribute, whether or not the received data packet is important, and   the control unit issues the interrupt immediately to the central processing unit when the judging unit judges that the received data packet is important.   
     
     
         18 . The network transmission/reception device of  claim 17 , wherein
 the attribute is type information that indicates a type of the data packet that is either a realtime packet or a not-realtime packet, where the realtime packet needs consideration of delay time, and the not-realtime packet does not need consideration of delay time,   the analyzing unit obtains a type from the received data packet by analyzing the received data packet, and   the judging unit judges that the received data packet is important when the type obtained by the analyzing unit indicates the realtime packet.   
     
     
         19 . The network transmission/reception device of  claim 17 , wherein
 the attribute is application information that indicates an application by which the data packet should be processed,   the network chip is connected to the network but is not connected in an application level, and preliminarily stores specification information that indicates an application specified by the central processing unit,   the analyzing unit analyzes whether or not the received data packet is a data packet of an application, and   when the analyzing unit analyzes that the received data packet is a data packet of an application, the judging unit judges, in accordance with the application information included in the received data packet, whether or not the received data packet is a data packet of the application indicated by the specification information, and judges that the received data packet is important when the judging unit judges that the received data packet is a data packet of the application indicated by the specification information.   
     
     
         20 . The network transmission/reception device of  claim 19 , wherein.
 the application information is a first port number for identifying an application by which the data packet should be processed,   the specification information is a second port number for identifying the application specified by the central processing unit, and   the judging unit judges that the received data packet is a data packet of the application indicated by the specification information when the first port number matches the second port number.   
     
     
         21 . The network transmission/reception device of  claim 17 , wherein
 the attribute is a network identifier for identifying the network,   the network chip is not connected to the network and preliminarily stores a specification identifier for identifying a network specified by the central processing unit,   the analyzing unit obtains the network identifier from the received data packet by analyzing the received data packet, and   the judging unit judges whether or not the network identifier obtained from the received data packet matches the preliminarily stored specification identifier, and judges that the received data packet is important when the judging unit judges that the network identifier matches the specification identifier.   
     
     
         22 . The network transmission/reception device of  claim 21 , wherein
 the data packet including the network identifier is a beacon packet,   the analyzing unit obtains the network identifier from the received beacon packet by analyzing the received beacon packet, and   the judging unit judges whether or not the network identifier obtained from the received beacon packet matches the specification identifier.   
     
     
         23 . The network transmission/reception device of  claim 17 , wherein
 the attribute is destination information that indicates a transmission destination of the data packet,   the analyzing unit obtains the destination information by analyzing the received data packet, and   the judging unit judges whether or not the transmission destination indicated by the destination information is the device that includes the network chip, and judges that the received data packet is important when the judging unit judges that the transmission destination indicated by the destination information is the device that includes the network chip.   
     
     
         24 . The network transmission/reception device of  claim 23 , wherein
 the destination information is a destination IP address for identifying a transmission destination device,   the network chip preliminarily stores a device IP address that is assigned to the device that includes the network chip, and   the judging unit judges that the data packet is destined for the device that includes the network chip when the device IP address matches the destination IP address.   
     
     
         25 . The network transmission/reception device of  claim 16 , wherein
 the received data packet includes type information that indicates a type of the data packet that is either a realtime packet or a not-realtime packet, where the realtime packet needs consideration of delay time, and the not-realtime packet does not need consideration of delay time,   the central processing unit processes one or more realtime packets stored in a predetermined storage area in a transmission process in which one or more data packets are transmitted to the external device,   the network chip manages times at which the one or more data packets are transmitted in the transmission process,   the analyzing unit obtains the type information from the received data packet, and stores the received data packet into the predetermined storage area when the type information indicates the realtime packet,   when the type information indicates the realtime packet, the judging unit judges whether or not a time period until a next data packet transmission is equal to or larger than a predetermined time period that is allowed for as a delay time, and   the control unit issues the interrupt immediately to the central processing unit when the judging unit judges that the time period until the next data packet transmission is equal to or larger than the predetermined time period.   
     
     
         26 . The network transmission/reception device of  claim 25 , wherein
 the network chip includes a time storage area preliminarily storing a transmission time interval at which data packets are transmitted, and manages the times at which the one or more data packets are transmitted, in accordance with the transmission time interval.   
     
     
         27 . The network transmission/reception device of  claim 25 , wherein
 the network chip preliminarily stores history information that indicates transmission times at which a plurality of data packets were transmitted respectively in past, and   the judging unit detects a transmission time at which a next data packet is to be transmitted, in accordance with the history information, and judges whether the detected transmission time is within a predetermined time range.   
     
     
         28 . The network transmission/reception device of  claim 16 , wherein
 data packets transmitted from the external device are classified into a plurality of types,   the external device transmits data packets of a same type to the network chip in one burst transfer period, where a plurality of burst transfer periods are provided respectively in correspondence with the plurality of types of data packets,   the network chip preliminarily stores time periods of the plurality of burst transfer periods that correspond to the plurality of types of data packets, and receives data packets of a same type in one burst transfer period,   the analyzing unit analyzes a data packet that is received first in a burst transfer period and obtains a time period of the burst transfer period corresponding to a type of the received data packet,   the judging unit judges whether or not a current time is within the burst transfer period based on the obtained time period of the burst transfer period, and   the control unit does not issue the interrupt immediately to the central processing unit when the judging unit judges that the current time is within the burst transfer period.   
     
     
         29 . The network transmission/reception device of  claim 28 , wherein
 the network chip stores one or more data packets, which were received during an interrupt process, into a predetermined packet storage area,   after a burst transfer is completed, the judging unit judges whether a predetermined time period has passed since a receipt of a start data packet that is stored first in the predetermined packet storage area, and whether number of data packets stored in the predetermined packet storage area is equal to or larger than a predetermined number, and   the control unit issues the interrupt immediately to the central processing unit when the judging unit judges either that the predetermined time period has passed since the receipt of the start data packet or that the number of data packets stored in the predetermined packet storage area is equal to or larger than the predetermined number.   
     
     
         30 . The network transmission/reception device of  claim 28 , wherein
 after a burst transfer is completed, the judging unit judges that the interrupt should be immediately issued, and   the control unit issues the interrupt immediately to the central processing unit when the judging unit judges that the interrupt should be immediately issued.